--
-- ~~~ helper utils
--

-- string -> hex
function string.tohex(str)
    return (str:gsub(".", function (c)
        return string.format("%02X", string.byte(c))
    end))
end

-- hex -> string
function string.fromhex(str)
    return (str:gsub("..", function (cc)
        return string.char(tonumber(cc, 16))
    end))
end